Efficient and effective delivery of cross-border and cross-sectoral eGovernment public services is crucially dependent on interoperability, provision of which directly contributes to the achievement of the goals of the Digital Agenda for Europe in particular and the Europe 2020 Strategy in general. In this context, main issues, knowledge units, best practice, and legal base of interoperability must be done fully understandable for all (staff of local, regional, and national public administrations, national institutions and agencies, managers of eGovernment projects, public service developers, policy makers, etc.) who are involved in defining, designing, and implementing Europe-wide public services. However, at the moment there are no known learning courses on interoperability in the EU member countries. The LLP Leonardo da Vinci project “ELGI - eLearning for eGovernment” addresses this issue and aims at the development of an innovative e-learning course for acquiring knowledge concerning interoperability. The e-course is intended to be useful for three main target groups: decision makers responsible for the process of legislating in the field of eGovernment, public administration staff who are/will be users of public services, and contractors or, in other words, organizations involved in development and delivery of public services. The current paper presents work-in-progress related to the design of the mentioned e-course. It covers all main aspects of the design starting from steps that were undertaken to create an information base needed for production of the e-course content and finishing with the detailed specification of the e-course structure. Therefore, the paper specifies the information base of the e-course, course aims, target groups, organization of learning process, modules, and topics. Moreover, each topic is presented in terms of its content and learning outcomes. The e-course will allow target groups to acquire all the actual knowledge on interoperability in one place.